TidyTuesday (2026) Week 9: Golem Grad Tortoise Data

The datasets this week come from the paper ‘Sex Ratio Bias Triggers Demographic Suicide in a Dense Tortoise Population’. This topic seemed so interesting that even media like the New York Times picked it up: ‘Constant Sexual Aggression Drives Female Tortoises to Walk Off Cliffs’.

Weights of Tortoises per season per year

1. Python code

import pandas as pd

import numpy as np

import matplotlib.pyplot as plt

clutch_size = pd.read_csv('https://raw.githubusercontent.com/rfordatascience/tidytuesday/main/data/2026/2026-03-03/clutch_size_cleaned.csv')

tortoise_body = pd.read_csv('https://raw.githubusercontent.com/rfordatascience/tidytuesday/main/data/2026/2026-03-03/tortoise_body_condition_cleaned.csv')

list(tortoise_body_condition_cleaned.columns.values)

individual_avg = tortoise_body.groupby(['individual', 'sex', 'year', 'season'])['body_mass_grams'].mean().reset_index()

mean_weight_season = individual_avg.groupby(['sex', 'year', 'season'])['body_mass_grams'].mean().round(2).reset_index()#

mean_weight_season['body_mass_kilograms'] = (mean_weight_season['body_mass_grams'] / 1000).round(2)

mean_weight_season['year_season'] = mean_weight_season['year'].astype(str) + ' ' + mean_weight_season['season']

mean_weight_season['sex'] = np.where(mean_weight_season['sex'] == "f", "Female", "Male")

season_order = {'spring': 1, 'summer': 2}

mean_weight_season['season_order'] = mean_weight_season['season'].str.lower().map(season_order)

mean_weight_season = mean_weight_season.sort_values(['year', 'season_order'])

pivot_data = mean_weight_season.pivot(
  index= 'year_season',
  columns='sex',
  values='body_mass_kilograms'

)

pivot_data.plot(kind='bar', figsize=(10, 6))

plt.title('Mean Plateau Tortosie Body Weight Over the Seasons and Years')

plt.xlabel('Season')

plt.ylabel('Body Weight (kg)')

plt.legend(title='Gender')

plt.xticks(rotation=45)

plt.tight_layout()

plt.show()